2 BULLETIN 709, U. S. DEPARTMENT OF AGRICULTURE. 
cipally by the use of salt and other preservatives and by protection 
from the air, and it was only for limited periods and in moderate 
quantities that they were preserved in the fresh state by holding 
them at reduced temperatures. The more palatable and more nutri- 
tious character of these products when preserved in the fresh state 
has given such encouragement to further use of this method of preser- 
vation that a complete transformation has resulted in the character 
and economic importance of the storage industry. Since the year 
1890 mechanical refrigeration has assumed great importance in the 
preservation and marketing of perishable and semiperishable prod- 
ucts, and the present importance of the storage industry is in large 
measure due to the adoption and development of this process. 
Aside from the carrying over of perishable and semiperishable 
foods in household economy from the season of production to the sea- 
son of nonproduction, there is in the business world a sufficient motive 
for such preservation in the profit to be gained by buying at lower 
prices in times of plenty for sale at higher prices in times of scarcity. 
The commercial motive has been an incentive in the business of stor- 
ing and preservation of foods at all times, and it exerts an equal 
force in the work of the cold-storage industry. The consequences, 
however, are not entirely commercial. Just as in the household the 
family in the season of nonproduction has the use and enjoyment 
of the food saved from the season of production, so in the commer- 
cial world the preservation of foods for seasons and years of scarcity 
is provided for by the accumulation of a surplus in times of plenty. 
The development of the cold-storage industry has made possible the 
holding of perishable foods in substantially the same condition as 
that in which they were first produced ; and the quantities that will 
be held in the future under mechanical refrigeration need be limited 
only by the powers of production of foods and of providing such 
means of storage and by the prospective demand. Accordingly there 
have already resulted, and in the future there may be expected to 
result in even greater degree, economic consequences of the utmost 
importance. 
The preservation of these articles in the fresh state from the season 
of greatest production to the seasons of scarcity tends to greater uni- 
formity of prices throughout the year. On the one hand it tends to 
relieve a glutted market, and on the other hand it not only provides 
a supply in the season of nonproduction of commodities which could 
not be had at such times in the fresh state at all, but also provides a 
larger supply, consequently at lower prices, of such products as 
butter and eggs, which otherwise could be had only in smaller quan- 
tities- Of still greater consequence than the equalization of prices is 
the conservation and avoidance of waste in the season of large supply 
and the larger consumption because of less excessive prices in the 
